BMMCC FPN

I know this has been previously discussed (to death) but after a good amount of testing I'm afraid I have an "above-average" amount of FPN in my BMMCC. It shows up with plenty of light and a properly exposed image.

Any suggestions? Obviously I can't send it in to BMD for a repair as they don't make it anymore.

Thanks all, trying not to freak out but you know how it goes sometimes...

Alternatively...if anyone is looking to sell a BMMCC with no to minimal/normal FPN let me know!

Being fixed pattern, you could try the subtraction approach.

Not a bad idea, but it seems like it may be beyond that given how easily and strongly it appears.

I would love to buy a working unit if possible, not quite ready to give up on this camera yet haha

Can you share DNG sample? Is it looks better if shoot ProRes? It is complicated to discuss FPN problem source and don't see how it looks.

FPN may be very different from camera to camera, so you may be luck or not. It is usually became visible if apply Noise Reduction before increasing Exposure (shoot as native ISO 800 underexposed by 2-3 stops, in Resolve apply noise reduction, and then bring image to normal Exposure by Linear gain adjustment node):


From 4 stops underexpose FPN became too visible:


See more test images here viewtopic.php?f=21&t=65149&p=543725#p543876

I also attempt to find a way to remove it, but subtract frame don't works well in BMMCC because when you subtract FPN from one tonal range you add new FPN to another tonal range. Also that is rather complex process and took time and final result unpredictable especially for video when your image is changing from frame to frame.

P.S. I still keep sample frames from early BMPCC (Original Pocket Camera) review on EOSHD that where shoot underexposed in low light but magically have no FPN at all. Even if i apply same noise reduction method to them. Maybe early sensor batches where better, maybe it is due different cooling system on BMPCC...

That raises another question: is you camera getting too hot?

That raises another question: is you camera getting too hot?

That shouldn't be the case with the BMMCC because it has active cooling; the original BMPCC does not and was more susceptible to overheating, yet doesn't exhibit FPN.

I wonder what would happen if you could temporarily disable the fan in the BMMCC (you'd want to avoid shooting at 60fps, which would almost certainly cause overheating without the fan) -- given that the sensors in the original BMPCC and the BMMCC are nearly identical it seems the only variable in the equation is the active cooling. So maybe the problem is that the fan is causing some sort of uneven cooling that's leading to FPN. Either that or it's variations across individual sensors.

Thanks for jumping in guys!

It’s definitely not overheating, and I don’t have any dng files to post, but based on what I’ve seen it certainly seems like I may have just gotten a “bad” sensor, or had bad luck and got a poor sensor as far as that variation goes.